2009LC headlights upgrade with 2013LC headlights

[Ronwed]

I have replaced my 2009 LC headlights with 2013 LC headlights and purchased the wiring adapter harness that was mentioned in one of the posts about this upgrade.
I am having these issues.
When I start the vehicle with the lights off, the high beams come on and the passenger one is very dim, while the drivers' side is bright. I checked the voltage on the passenger high beam and it shows negative (-) 12.9 volts.
If I use the turn signal, both high beams flash at the same time, instead of the correct turn signal. This happens at all switch locations, unless I turn the lights to on.
When I turn the lights on, (the one below "auto"), everything works properly.

I have attached the wiring diagrams for 09 and 13 and it appears there is some differeces. I am trying to figure out how to make this all work without having to rewire/splice everything.

 

[Boston Mangler]

Following

 

[OregonLC]

Not sure how it works on the 2009, but the 2013 DRLs put the high beam circuit in series. So you get effectively 6v through each bulb. I believe Toyota did this to prolong bulb life while still providing daytime DRL visibility. I wonder if this is creating a stray ground path that is causing the wonkiness.

Do you have the capability in the settings screen for your 2009 to turn off the DRL function to see if that remedies some of the issues?

 

[Ronwed]

Not sure how it works on the 2009, but the 2013 DRLs put the high beam circuit in series. So you get effectively 6v through each bulb. I believe Toyota did this to prolong bulb life while still providing daytime DRL visibility. I wonder if this is creating a stray ground path that is causing the wonkiness.

Do you have the capability in the settings screen for your 2009 to turn off the DRL function to see if that remedies some of the issues?

Thanks for that info. I’ll look to see if I can turn off DRL and see what happens. I’m not sure why I get +12v on the drivers side and get -12v on the passenger side.

 

[OregonLC]

There is no such thing as negative voltage. There is 12v+ and ground, the negative just indicates that your probes are reversed. Not sure which pins you're checking, but it could simply be that to get the 6V DRL function to work the computer swaps a hot with a ground.

 

[Ronwed]

Not sure how it works on the 2009, but the 2013 DRLs put the high beam circuit in series. So you get effectively 6v through each bulb. I believe Toyota did this to prolong bulb life while still providing daytime DRL visibility. I wonder if this is creating a stray ground path that is causing the wonkiness.

Do you have the capability in the settings screen for your 2009 to turn off the DRL function to see if that remedies some of the issues?

OregonLC - I checked and there is no option to turn off the DRL's on my 2009. In looking at the 09 vs 13 wiring diagram, I notice the 09 has a wire connecting from the Head Lo Relay to the DRL No. 4 Relay whereas the 13 goes direct from the battery to the DRL MOD Relay without going thru the Low Beam Relay.

 

[mattgentoo]

Hi,
Any progress on your upgrade?
I would be interested to performed the same on my 08 LC.
Thanks!